Am I mistaken, or does Steve hold tension on a line of solder using his teeth ? Or is that bus wire ? Surprised he isn't concerned about lead poisoning.
Looks like solder to me. I can't imagine holding some solder (usually only ~40% lead) in your teeth would give you that much exposure to be an issue. But I suppose doing it all day, every day, for years could add up.
Of course, liquids have vapor pressure at any temperature between melting and boiling. I think there is no question that whatever vapor there is can be carried by convection along with the hot gases.
It's not my place to provide evidence, as I'm not the one making a positive assertion. It'd be nice if someone has done formal research on lead levels in electronics workers, but I've never seen anything like that posted, just a lot of scaremongering and ill-informed legislation.
Edit: you do realize what the term elemental lead refers to, correct? Here's another complex multi-syllable word that's worth of study by HN moderators: bioavailability.